Brazil's Supreme Court has been gripped by its worst institutional crisis since the return of democracy in the 1980s, as two rival justices traded public insults and accusations during a live-broadcast hearing in Brasília. At the centre of the row are justices Alexandre de Moraes and André Mendonça, whose feud has become entangled with a sprawling banking scandal involving Banco Master, a collapsed lender whose owner allegedly made payments to figures across Brazil's political and judicial establishment. With polls showing a near dead heat between President Luiz Inácio Lula da Silva and far-right challenger Flávio Bolsonaro ahead of October's election, analysts warn the turmoil risks deepening public distrust and intensifying an already bitter campaign.